Driven by the desire to reduce automobile weight and improve fuel efficiency, the auto industry has dramatically increased aluminum use in automobiles in recent years. To further reduce weight, more iron and steel components need to be replaced with aluminum. Aluminum and its alloys have many attractive properties. Poor wear resistance, however, and low working temperature limit its potential wider uses. To solve the above noted problems, various methods of manufacturing lightweight components made of ceramic-reinforced aluminum metal matrix composites (MMC) or so-called ceramic metal composites (CMC) have been disclosed. In these methods, molten aluminum mixed with ceramic particles is poured into a mold to produce a component, or molten aluminum infiltrates a porous ceramic preform to produce a component. The aluminum MMC does improve wear resistance, but creates other problems. The aluminum MMC is very brittle, with about a 90% reduction in ductility with 10–15 vol. % ceramic particles in an aluminum matrix. As a result, monolithic aluminum MMC components are more prone to sudden catastrophic failure. This would likely cause serious liability problems if MMC was used for safety-sensitive parts such as a brake rotor and drum. In addition, it is difficult to machine aluminum MMC to final specifications. The SiC or alumina in the aluminum MMC wears cutting tools very fast. Also, aluminum MMC brake rotors do not stand the friction heat well, causing adhesive wear and galling on the rotor rubbing surfaces. Finally, aluminum MMC material is also expensive.
U.S. Pat. No. 5,183,632 discloses a method of manufacturing an aluminum disc rotor with aluminum composite rubbing surfaces which consists of aluminum and ceramic powders and are bonded to the aluminum rotor body by heating and pressing.
U.S. Pat. No. 5,224,572 discloses a lightweight brake rotor with a thin ceramic coating on rubbing surfaces.
U.S. Pat. No. 5,884,388 discloses a method of manufacturing a friction-wear aluminum part by thermally arc-spraying a mixture of aluminum and stainless steel onto the wear surface.
U.S. Patent Application Pub. No. 2001/0045332 A1 discloses a titanium or aluminum brake disc bonded with stainless steel on the rubbing surfaces by brazing.
Japanese Patent Application No. JP-A No. H9-42339 discloses an aluminum brake disc bonded with an alloy steel on the rubbing surfaces by explosive cladding.